Solid Additives for Spontaneously Spreading-Processed Organic Photovoltaics.

Area of Science:

• Materials Science
• Organic Electronics
• Renewable Energy

Background:

• Spontaneous spreading (SS) is a solution-processed fabrication method for organic photovoltaics (OPVs).
• Current SS methods face challenges in achieving uniform film thickness and homogeneous morphology.
• Developing efficient and reproducible OPV fabrication is crucial for renewable energy advancements.

Purpose of the Study:

• To develop an improved SS process for fabricating organic photovoltaics (OPVs).
• To address limitations in film uniformity and morphology control in SS-processed OPVs.
• To introduce solid additives as a strategy for optimizing SS film formation.

Main Methods:

• Developed a spontaneous spreading (SS) process using the green solvent o-xylene.
• Utilized phenanthrene (PAT) as a solid additive to regulate interfacial tension and drying time.
• Fabricated uniform SS films on a water surface for OPV active layers.

Main Results:

• Achieved uniform SS-film formation on the water surface.
• Phenanthrene (PAT) additive improved molecular packing and phase-separated morphology.
• The resulting OPV device demonstrated a champion power conversion efficiency of 16.4%.

Conclusions:

• Introduced solid additives for the first time in SS-processed OPVs to control film-forming kinetics and morphology.
• Demonstrated a versatile and simple approach for fabricating solution-processable and reproducible OPVs.
• The novel SS method offers a promising strategy for efficient organic photovoltaic device fabrication.